Roxanne: To protect declining elephant herds from poachers seeking to obtain ivory, people concerned about such endangered species should buy no new ivory. The new ivory and old ivory markets are entirely independent, however, so purchasing antique ivory provides no incentive to poachers to obtain more new ivory. Therefore, only antique ivory—that which is at least 75 years old—can be bought in good conscience.

Salvador: Since current demand for antique ivory exceeds the supply, many people who are unconcerned about endangered species but would prefer to buy antique ivory are buying new ivory instead. People sharing your concern about endangered species, therefore, should refrain from buying any ivory at allthereby ensuring that demand for new ivory will drop.

Speaker 1 Summary
Roxanne argues that people who want to protect elephants from poachers should only buy antique ivory. This is because there are separate markets for new ivory and antique ivory, so buying antique ivory doesn’t increase the demand for new ivory. Thus, although new ivory is harmful, buying antique ivory doesn’t incentivize poaching.

Speaker 2 Summary
Salvador argues that people who want to protect elephants should not buy any ivory at all. Why? There’s more demand for antique ivory than supply, so some people buy new ivory instead because antique ivory is too expensive. By not buying any ivory at all, people can lower the demand for antique ivory, therefore redirecting some new-ivory sales and reducing the demand for poaching.

Objective
We’re looking for a point of disagreement. Roxanne and Salvador disagree about whether buying antique ivory threatens elephants.

A
there are substances that can serve as satisfactory substitutes for ivory in its current uses
Neither Roxanne nor Salvador mentions any substances that can substitute for ivory. The discussion is about antique versus new ivory, not ivory versus something else.
B
decreased demand for antique ivory would cause a decrease in demand for new ivory
Roxanne claims that the demand for antique ivory is unrelated to the demand for new ivory. Salvador argues that lowering the demand for antique ivory can lower the demand for new ivory by redirecting some buyers. This is the point of disagreement.
C
people should take steps to avert a threat to the continued existence of elephant herds
Roxanne and Salvador both discuss only what people should do if they want to help protect elephants. Neither directly states that people should protect elephants, but it would be fair to assume that they both agree it’s a good idea. Either way, no disagreement here.
D
a widespread refusal to buy new ivory will have a substantial effect on the survival of elephants
Neither speaker talks about how impactful a refusal to buy new ivory would be. Even Roxanne, who proposes a boycott of new ivory as a way to protect elephants, doesn’t specify how much this could do to help the species.
E
people concerned about endangered species should refuse to buy ivory objects that are less than 75 years old
Roxanne agrees with this, and so does Salvador. Roxanne states that people with this concern should not buy ivory less than 75 years old. Salvador goes even further and says that those people should not buy any ivory at all, which includes new ivory.

34 comments

A television manufacturing plant has a total of 1,000 workers, though an average of 10 are absent on any given day for various reasons. On days when exactly 10 workers are absent, the plant produces televisions at its normal rate. Thus, it is reasonable to assume that the plant could fire 10 workers without any loss in production.

Summarize Argument
The author concludes that the manufacturing plant could fire 10 of its 1000 workers without any loss in production. Why? Because an average of 10 workers are usually absent anyway. And, when 10 workers are absent, production continues at the usual rate.

Identify and Describe Flaw
The author notes that 10 workers are usually absent on any given day. However, he fails to establish that it’s the same 10 people every day. Quite possibly, which workers are absent varies from day to day.
If so, firing 10 workers would decrease the manufacturing plant’s workforce. In addition to lacking the absentee workers, the plant would now lack the fired workers. And thus production might decrease.

A
ignores the possibility that if 10 workers were fired, each of the remaining workers would produce more televisions than previously
If the remaining workers produced more televisions, production would not go down—which would strengthen the author’s conclusion. So this can’t be the flaw.
B
fails to show that the absentee rate would drop if 10 workers were fired
The author’s conclusion requires the absentee rate to drop after the firings—but he doesn’t show that it would. Suppose the absentee rate stayed the same among the remaining workers. The workforce would then be missing both the absentee workers and the fired workers.
C
takes for granted that the normal rate of production can be attained only when no more than the average number of workers are absent
The author doesn’t presume that the normal rate of production can only be attained if the average number of workers or fewer are absent. He merely says that it is in fact attained when that number is absent.
D
overlooks the possibility that certain workers are crucial to the production of televisions
We have no specific reason to believe that the author overlooks this—unlike the flaw in (B).
E
takes for granted that the rate of production is not affected by the number of workers employed at the plant
This goes far beyond what the author is arguing: it would mean that even reducing the number of workers by 80% would not affect the rate of production! The author is only contending that the loss of 10 workers wouldn’t affect production.

42 comments

Political candidates’ speeches are loaded with promises and with expressions of good intention, but one must not forget that the politicians’ purpose in giving these speeches is to get themselves elected. Clearly, then, these speeches are selfishly motivated and the promises made in them are unreliable.

Summarize Argument

The author concludes that politicians’ speeches are selfishly motivated and their promises are unreliable. She supports this by saying that their main goal in giving speeches is to get elected.

Identify and Describe Flaw

This is the cookie-cutter “ad hominem” flaw, where the author attacks the person or group making an argument instead of the argument itself.

Here, the author assumes politicians' promises are unreliable just because they have other motives for making those promises. However, having ulterior motives doesn't necessarily make a promise unreliable.

A
The argument presumes, without providing justification, that if a person’s promise is not selfishly motivated then that promise is reliable.

The author assumes the opposite of (A). She assumes, without providing justification, that if a person’s promise is selfishly motivated then that promise is unreliable.

B
The argument presumes, without providing justification, that promises made for selfish reasons are never kept.

The author assumes, without providing justification, that promises made with ulterior motives are unreliable. She doesn’t claim that the promises are never kept, just that they can’t be relied upon. Perhaps some of these promises are still kept, even though they’re unreliable.

C
The argument confuses the effect of an action with its cause.

The author’s argument doesn’t use causal reasoning at all, so she never confuses an effect with a cause.

D
The argument overlooks the fact that a promise need not be unreliable just because the person who made it had an ulterior motive for doing so.

In other words, the author overlooks the fact that a promise could still be reliable, even though the person who made it had an ulterior motive for doing so. Having ulterior motives doesn't necessarily make a promise unreliable.

E
The argument overlooks the fact that a candidate who makes promises for selfish reasons may nonetheless be worthy of the office for which he or she is running.

The author never makes any claims about whether candidates who make promises for selfish reasons are worthy of their office. She just claims that their promises are unreliable.


10 comments